AD 91-03-18

91-03-18 BRITISH AEROSPACE: Amendment 39-6886. Docket No. 90-NM-198-AD.

Applicability: All Model BAe/DH/HS/BH-125 series airplanes, equipped with Aircraft Products Company (APC) warming ovens having part numbers 255B-LH-28/115, 255B-RH-28/115, or 255-362, certificated in any category.

Compliance: Required as indicated, unless previously accomplished.

To prevent a warming oven fire and to provide additional overheat protection, accomplish the following:

A. Within 60 days after the effective date of this AD, accomplish the following:

1. Inspect the wire insulation inside the warming oven in accordance with British Aerospace Service Bulletin 25-54-9758A&B, Revision 1, dated August 14, 1989. If the oven wiring or thermostat wiring is damaged, prior to further flight, replace the wiring and/or thermostat, as appropriate, in accordance with the service bulletin.

2. Modify the warming ovens by installing an additional thermostat and a new switch, in accordance with British Aerospace Service Bulletin 25-54-9758A&B, Revision 1, dated August 14, 1989.

NOTE: British Aerospace Service Bulletin 25-54-9758A&B references Aircraft Products Company (APC) Service Bulletins 255B-25-002, Revision A, dated June 22, 1989, and 255-25-003, dated May 26, 1989, for additional instructions.

B. An alternate means of compliance or adjustment of the compliance time, which provides an acceptable level of safety, may be used when approved by the Manager, Standardization Branch, ANM-113, FAA, Transport Airplane Directorate.

NOTE: The request should be submitted directly to the Manager, Standardization Branch, ANM-113, and a copy sent to the cognizant FAA Principal Inspector (PI). The PI will then forward comments or concurrence to the Manager, Standardization Branch, ANM-113.

C. Special flight permits may be issued in accordance with FAR 21.197 and 21.199 to operate airplanes to a base in order to comply with the requirements of this AD.

All persons affected by this directive who have not already received the appropriate service documents from the manufacturer may obtain copies upon request to British Aerospace, PLC, P.O. Box 17414, Dulles International Airport, Washington, D.C. 20041-0414. These documents may be examined at the FAA, Northwest Mountain Region, Transport Airplane Directorate, 1601 Lind Avenue S.W., Renton, Washington.

This amendment (39-6886, AD 91-03-18) becomes effective on March 11, 1991.